Teachers' leaders have demanded an end to the funding of more faith schools, saying pupils risked being indoctrinated by religious extremists.

They made the call after it was revealed that 42 of the first 100 of Tony Blair's flagship academies had Christian sponsors.

Delegates at the 160,000-strong Association of Teachers and Lecturers' conference in Gateshead warned that the increasing number of faith schools posed a threat to integration and provided "fertile ground for religious and ethnic conflicts".

The Rev Chris Wilson, chaplain at Cambridge Regional College, supporting the ban on funding, said: "We need to be concerned that some of the faith communities have agendas which are at odds with reason and progress and the interests of science. My aspiration would be to have a secular education system in which all faiths are honoured and respected."

Delegates cited the teaching of creationism in science lessons as a major concern. Schools sponsored by the Vardy Foundation, run by Sir Peter Vardy, have been accused of doing this.

Dr Mary Bousted, the union's general secretary, said: "What else is going on? Are people being taught that it is all right to be homophobic? Government policy - particularly through the academies programme - is about a rapid increase in faith schools.

"ATL members are worried that this rate of increase will see fundamentalists having a growing influence on the school curriculum."

Andy Ballard, from Somerset, added: "Schools should focus on teaching kids to be decent human beings. They should take pupils of all faiths and of none in equal measure."

However, Elizabeth Green, from Wiltshire, argued: "Faith schools have a place in our society and all parents should have the right to choose one for their child if they so wish."

The conference voted to demand a ban on the funding of any future faith schools. It also called on ministers to give cash aid to any existing faith schools in the state sector that wanted to become secular. At present 15 per cent of the capital budget of voluntarily aided faith schools comes from their church group.

However, they voted against a demand for new laws banning the teaching of creationism and intelligent design as an alternative to evolution in science lessons, after opposition from religious education teachers. The Royal Society - Britain's most prestigious science body - called for a ban, saying children were confused by the teaching of the Bible's creation story in science lessons.

This weekend Britain's biggest teachers' union, the National Union of Teachers, will be urged to back an end to all state funding of faith schools. Delegates at its conference in Torquay will also cite growing fears of indoctrination of pupils by fundamentalists.

A spokesman for the Department for Education and Skills defended the funding of further faith schools - saying that parents should have the right to send their children to an academy sponsored by a faith group if they wanted to.

Under the academies programme, the sponsor can control the governing body and determine what is to be included in the curriculum. Mr Blair is seeking to give similar powers to the new independently run "trust" schools he is planning to set up.

Meanwhile, the Schools minister, Jacqui Smith, will today unveil a £50m package to boost vocational studies in schools. The money will be used to train teachers to teach five diplomas, to be introduced in 2008 as an alternative to GCSEs.

Sponsored academies

* The United Learning Trust, an Anglican charity linked to the United Church (seven academies)

* The Oasis Trust, a Christian charity founded by the Baptist minister and TV presenter the Rev Steve Chalke (four)